The invention relates to the hydraulic actuation of a folding roof of a motor vehicle, such as a passenger car of the cabriolet type.
In particular, the present invention relates to a hydraulic actuating unit which is designed to be integrated in a preassembled folding roof unit, which in turn is designed to be mounted in a motor vehicle as a single unit with the actuating unit integrated therein. In this case, the said preassembled folding-roof unit comprises a folding roof with a foldable cover and, for example, with a rear window and, furthermore, a framework for supporting the cover. The framework comprises a pivotable main bow, which can move between a pivoted-up position and a pivoted-down position, and a pivotable rear bow for moving a rear section of the folding roof. The hydraulic actuating unit comprises a hydraulic main bow actuator for pivoting the main bow, and a hydraulic rear bow actuator for pivoting the rear bow.
A hydraulic actuating unit adapted for integration into a preassembled folding roof unit of a motor vehicle, which preassembled folding roof unit in turn is adapted for mounting as a single unit in a motor vehicle with the hydraulic actuating unit integrated therein, is known from U.S. Pat. No. 6,149,221 (first described in NL Pat. No. 1,008,455) in the name of the present applicant.
In this known hydraulic actuating unit, there are, as is customary, two main bow actuators, which are connected hydraulically in parallel, and two rear bow actuators, which are connected hydraulically in parallel. To control the movement of these actuators, in the known actuating unit three electromagnetically actuable 3/2-control valves are incorporated in the known actuating unit. Furthermore, there is a hydraulic AND valve whichxe2x80x94as explained in NL 1008455xe2x80x94allows the number of relatively expensive electromagnetically actuated control valves to be reduced.
An advantageous aspect of the known actuating unit is that only two connecting lines are required between the said actuating unit, on the one hand, and the pump/reservoir unit, on the other hand, which is mounted at a different location, for example in or in the vicinity of the boot space, in the motor vehicle. It is known for these connecting lines to be completely or partially designed as flexible hydraulic hoses.
It is an object of the present invention to propose measures which further improve the hydraulic actuating unit which is to be integrated in the preassembled folding-roof unit, without it being necessary to increase the number of connecting lines to the pump/reservoir unit, so that two connecting lines are sufficient. In particular, it is an object of the invention to propose measures which allow further simplification of the said hydraulic actuating unit, so that it is preferably possible to achieve a reduction in cost price.
The present invention provides a hydraulic actuating unit for integration into a preassembled folding roof unit of a motor vehicle.
Said preassembled folding roof unit comprises a folding roof with a foldable cover and a framework for the cover, which framework comprises a pivotable main bow, which is moveable between a pivoted-up position and a pivoted-down position, and a pivotable rear bow for moving a rear section of the folding roof.
The hydraulic actuating unit comprises a hydraulic main bow actuator for pivoting the main bow and a hydraulic rear bow actuator for pivoting the rear bow, the main bow actuator and the rear bow actuator being of the double-acting type, each having a first and a second variable working chamber, which are delimited by a piston of the hydraulic actuator in question.
The hydraulic actuating unit also comprises at least one actuable two-position control valve, which control valve has an outlet port, an inlet port and a reservoir port, the outlet port being connected to a working chamber of the main bow actuator and/or a working chamber of the rear bow actuator, and which control valve, in a first position thereof, connects the associated outlet port to the reservoir port and, in a second position thereof, connects the associated outlet port to the inlet port of the control valve.
The hydraulic actuating unit has two hydraulic connection ports, namely a first connection port, which is in communication with the inlet port of at least one actuable two-position control valve, and a second connection port, which is in communication with the reservoir port of each control valve.
The first connection port and the second connection port of the hydraulic actuating unit are each provided with a coupling element for coupling said connection port to a corresponding coupling element, which is in communication with a hydraulic circuit.
In the hydraulic circuit at least one hydraulic pump/reservoir unit is incorporated, said pump/reservoir unit being adapted for mounting in the motor vehicle at a distance from the hydraulic actuating unit which is integrated in the folding roof unit.
The hydraulic pump/reservoir unit comprises at least one reservoir for hydraulic fluid and a pump which is connected to the reservoir for delivering pressurized hydraulic fluid.
According to the invention in the hydraulic actuating unit the reservoir port of each control valve is also connected to the first connection port. Furthermore a valve element with a non-return valve action opening towards the relevant connection port is provided in the connection between each reservoir port and the first connection port and in the connection between each reservoir port and the second connection port.
The last-mentioned measures lead to a saving of at least one (expensive) electromagnetic valve in the hydraulic actuating unit, which is integrated in the preassembled folding-roof unit, compared to the abovementioned prior art.
The present invention also relates to a preassembled folding-roof unit in which a hydraulic actuating unit of this type is integrated, and to a folding-roof installation which, in addition to the said folding-roof unit, comprises one or more further components, such as for example a (hydraulically drivable) tonneau-cover for covering a compartment for accommodating the open folding roof.
The present,invention also relates to a motor vehicle, in particular a passenger car of the cabriolet type, having a folding roof which can be actuated by means of an associated hydraulic actuating device according to the invention.
The invention, as well as advantageous embodiments and advantages thereof, are described in more detail in the following description with reference to a preferred embodiment.